Thanks for your replies guys. I had the car twice at BMW. Every time they replaced discs and pads they said that they were warped. In the end they blamed my style of driving as the cause of brake warpage and refused to replace them again under the same warranty. I could pay for a new set with new warranty they said. But I said that it would be pointless cose it's nothing to do with my driving style and I'd rather get an aftermarket set of discs. And so I did. Got a set of Bosch discs. Vibrating had stopped but only for 1.5k miles. Because I read a lot about worn bushings on control arms that can be the cause of the vibrations I decided to replace them with Lemforder ones. (I was assured by BMW mechanics that all bushings were fine)
Got them replaced and the discs machined down. You can see the old ones in pictures above. Everything seemed to be perfectly fine until a week ago when I started noticing vibrations on the steering wheel again.
The only things that haven't been replaced yet and could be responsible for vibrating are the thrust arms and the hubs. Should I replace them??? I'd rather not to without being 100% sure that this is the cause.
Do you guys have any ideas??? Please help...